Automatic calculation apparatus



March 19, 1940. K. s. LION AUTOMATIC CALCULATION APPARATUS Filed Feb.25, 1937 mql.

lllllllll llllljll|| lllll] l INVENTOR ffimf fibyflzed Lion ATTORNEYPatented Mar. 19, 1940 UNITED STATES PATENT OFFICE 2 Claims.

10 distance, thicknesses of filters, loads of tubes, and

the like.

Until now, the determination of these values has had to be efifected bymeans of tables, curves,

nomograms, and slide rules, a procedure which necessitated alsomathematical operations. These methods, however, make possible theoccurrence of various errors, calculating mistakes and mistakes indecimals, which mistakes may be costly and must be avoided, especiallyin medical X-ray 20 work where such errors may give rise to greatdanger. Other objects and features of the invention will be more fullyunderstood from the following description to be read in connection withthe 5 accompanying drawing in which: 7

Fig. 1 diagrammatically illustrates a conventional slide rule; v

Fig. 2 is a view in elevation of an apparatus embodying the invention;30 Fig. 3 is a view in elevation of an apparatus embodying the inventionin modified form;

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 3;

Fig.5 is a fragmentary sectional view taken on the line 55 of Fig. 3;and

Fig. 6 is a view inelevation of an apparatus embodying the invention inanother modified form.

The system is based on the ordinary slide rule 40 in which, according toFig'. 1, length B is added to length A. The length C equals the sum ofthe lengths A and B, and thus, when the scales are logarithmic theproduct AXB may then be read 01!. v

45 The length B, however, is not independent of the length A, inasmuchas its starting point is determined by the terminal point of line A, andthat means that the length B is determined by the value of anotherfactor. Thus, the length 50 B can be adjusted only after A has beendetermined. In order to'avoid this condition, which occurs in similarmanner with nomograms and which makes their use diflicult to lessexperienced operators, the following changes are made:

55 AccordingtoFlg. Zaribbon l'isflxedly con- In Germany June 29, 1936nected to and wound around the 'turnable roller D, runs over the rollerG and has its end fixed to the roller E. The rollers D and E arerotatably mounted on baseboard II but cannot be shifted, whereas theroller G may be shifted in the direction of the double arrow l2 eitherupwardly or downwardly, its position depending upon the spring F andupon how much ribbon is wound off from the rollers D and E.

If from the roller D, hearing an indicator I311, the length d is woundoff and from the roller E, bearing an indicator Ma, the length e iswound oil, the shifting of the roller G in the direction of the springequals (d+e)/2; that is, in proportion to the sum (d+e) If new, on thescales I3 and M at D and E, respectivelmlogarithms are put in place ofthe values it and e, and if the scale l5 at G shows half measure and islogarithmic also, then the indicator l6 associated. with the scale at G-will indicate the product dxe. The advantage of this arrangement lies inthe fact that the scales at D and E are fixed and can be simply andindependently adjusted and also that the result may be read ofi on aseparate scale, which gives the correct position to the decimal point. I

The separation of the two scales lends the possibility of furtherimproving the construction of the invention for cases in which the twofactors which are to be adjusted are dependent upon one another as, forinstance, in Fig. 2 where the value c is a function of the value d. Acalculation of this type might be the determination of the electricalinput to an X-ray tube, which is the product of current and voltage,there being a dependcut relationship between current and voltage becausethe voltage drops with increasing current. A further important exampleof such a calculation might be the determination of an X-ray dose as afunction of the tube voltage and the filter thickness, since theabsorbing capacity of the filter is largely dependentupon the voltage.

Thus, if the scale of the dependent factor is adjusted simultaneouslywith the adjustment of the other factor, problems such as thosementioned can be solved. An apparatus capable of such operation is showndiagrammatically in Fig.

3, which illustrates an arrangement basically similar to thatillustrated in Fig.' 2, in that it embraces a first fixed rotatableroller, 9. second fixed 5 rotatable roller, a flexible ribbon connectedto and wound about said rollers, and a third roller over which theribbon passes, the third "roller being urged by a spring or the like soas tb'hold taut the length of the ribbon which is notwound upon thefirst mentioned rolle'rs,-the third roller being provided with asuitable scale and pointer.

product of both values. The dropplng'ofthe. voltagewith increasingcurrent is taken into account by the fact that when the currentindicator is regulated on the current scale the adjustment of thisindicator automatically changes the volt-.

age scale. If then, the .voltageindlcator is adjusted to the desiredposition on the voltage scale which was previously shifted, the resultindicator will indicate on its scale the true value of the electricalinput, the voltage drop having I been considered.

It more than two factors are to be jointly considered to give a singleresult, as where X-ray dosage is to be determined from exposure time,voltage, current, distance and filter, then the following form of theinvention may be used; according to Fig. 4 a flexible ribbon Z that isfastened at point L lies around shiftable rollers M, N, O, and P. Theserollers are held in position by ribbons or rods fixed thereto, theirpoint of rotation being movable by these either upwardly or downwardly.Thereby, the point R is shifted as indicated on scale 8 by a pointer.The shifting of the pointer R on the scale 8 is. proportional to the sumof the shiftings m, n, o, and' p, and if all the scales arecorrespondingly divided logarithmically, indicates the product of m n op. I D

Since many changes may be made in the invention without departing fromthe scope thereof, it is intended that all matter set forth in the abovedescription, or shown in the accompanying drawing, be regarded asillustrative only and not in a limiting sense.

I claim:

1. A calculating apparatus of the character described, including a firstadjustably mounted member, first indicator means operatively assoelatedwith said first adjustable member, a first scale bearing element adaptedto cooperate with said first indicator means and being fixedly mounted,a second adjustably mounted member, second indicator means operativelyassociated with said second adjustable member, a second scale bearingelement adapted to cooperate with said second indicator means and beingadjustably mounted, an operating arm adjustable with said firstadjustable member and adapted to change the position of said secondscale bearing element in accordance with changes in the adjustment ofsaid first adjustable member, a third scale hearing element, thirdindicator means arranged in operative relationship with said third scalebearing element, and means including a flexible ribbon connected to saidfirst adjustable element and to'said second adjustable element forchanging the position of one of said last mentioned elements withrespect to the other in accordance with changes in the adjustment of atleast one of said two first mentioned adjustable members.

2. A calculating apparatus of the character described, including a firstadjustably mounted member, first indicator means operatively associatedwith said first adjustable member, a first scale bearing element adaptedto cooperate with element in accordance with changes in the adjustment'of said first adjustable member, said second adjustable scale bearingmember having an extending portion against which said operating armbears, athird scale bearing element, third indicator means operativelyassociated with saidv third scale bearing element, and means forchanging the position of one of said two last mentioned elements inaccordance with changes in the adjustment of said first and secondadjustable members.

KURT SIEGFRIED LION.

